Direction finder



a. 22, 1935. A. LEIB. 2,017,909

DIRECTION FINDER Filed July 8, 1953 INVENTOR AUGUST EIB ATroRNEYPatented Oct. 22, 1935 UNITED STATES PATENT OFFICE i g Y nmmififz mm i 7August Leib, Berlin, Germany, assignor to Telefunken Gesellschaft fiirDrahtlose Telegraphic m. b. 11., Berlin, Germany, a corporation ofGermany 4 .Claims.

This invention relates to a direction-finding receiver arrangementcomprising a rhythmically changed-over antenna.

It has been suggested in the prior art of receivers with rhythmicallychanged-over antennae to make the two connections distinguishable fromeach other by different acoustic identification marks or signs producedin the receiver outfit, say, two acoustic signals being difierent fromand complementary in reference to each other, and to contrast the volumeof the two in such a way that like volumes (in case of complementarysignals a continuous and invariable tone) indicate the proper adjustmentof the direction-finder in reference to the incoming beam, anddissimilar volumes a deviation to the right or the left-hand side. Ifone of the distinctive marks or signals is louder than the other, then adeviation to the right has happened, and vice versa. But this does notpreclude the chance of an error, for a mental effort must always be madeto recall as to which signal, when louder, corresponds to a departure tothe right, and which to a deviation to the left.

In order to relieve the memory entirely, the distinguishing signals ofthe two antenna leads, according to this invention, are produced in away preclusive of all chances of error or confusion by operating theleft earand right ear-phones of the headset independently of each other,and by alternately connecting the phones with the receiver at the rhythmwith which the change-over of the aerial occurs. In other words, in oneantenna connection, one hears only with the right ear, and in the otherantenna connection only with the left ear. Then, if the receptionperceivable with the right ear is stronger in volume, a deviation to theright from the course occurs, and vice versa. If the two intensities arealike, then the direction-finder is exactly set for the beacon. 7

One exemplified embodiment of the basic idea of the invention is shownin the drawing schematically, the same covering the particular casewhere, by the aid of a coil antenna A and a linear antenna B, adirectional cardioidal receiving characteristic is obtained. The changefrom one cardioidal receiving characteristic to the other beingsymmetric is efiected by the change of the relative sense of connectionof the two'antennae. The change-over of the antennae is effected, forinstance, by the aid of a mechanical commutator or switch Kl. Accordingto the invention, the

left telephone HI and the right telephone Hr are connected with thecontacts I, I, and'Z, 2, re-

spectively of a commutator or throw-over switch K2 synchronized with theantenna throw-over switch Kl so that the left and the right phone areunited with the output end of the receiver E in unison with the antennachanges. 5

In addition to this method of insuring distinction, the variousswitching operations can be differentiated furthermore by additionalacoustic identifications, such as dissimilar complementary acousticsignals.

I claim:

1. A receiver switching arrangement for a direction finder, comprising aplurality of switch blades and switch contacts, a linear antennaconnected to one of said switch blades, a coil antenna 15 havingcoupling means for coupling said coil antenna to a radio receiver, saidcoil antenna connected to contacts associated with one of the switchblades that is connected to said linear antenna, a radio receiverconnected to two of the other switch blades, a head set comprisingtelephone receivers for use with the right and left hand ear, saidtelephone receivers having separarate electrical connections connectedto the contacts of said radio receiver switch blades, and means forsimultaneously operating the radio receiver switch blades with saidantenna switch blades so that the telephone receiver for the left handear and one for the right hand car are changed over in synchronism withthe changes 0 in connection of said antenna. a

2. A receiver switching arrangement for a direction finder, comprising aplurality of switch blades and switch contacts, a linear antennaconnected to one of said switch blades, a coil antenna having a couplingtransformer for coupling said coil antenna to a radio receiver, saidcoil antenna connected to the contacts of one of said switch blades thatis connected to said linear antenna, said radio receiver connected totwo of the other switch blades, 2. head set comprising telephonereceivers for use with the right and left hand ear, said telephonereceivers having separate electrical connections connected to thecontacts of said radio receiver switch blades, and means forsimultaneously operating the radio receiver switch blades with saidantenna switch bladesso that the telephone receiver for the left handear and one for the right hand ear are changed over in synchronism withthe changes in connection of said antenna.

3. A receiver switching arrangement for a direction finder, comprising aplurality of switch blades and switch contacts, a linear antennaconnected to one of said switch blades, a coil antenna having aplurality of coils, one of said coils being grounded at the center pointthereof and being adapted for coupling said coil antenna to a radioreceiver, said coil antenna being connected to the contacts of that oneof said switch blades which is connected to said linear antenna, saidradio receiver being'connected to two others of said switch blades, ahead set comprising telephone receivers for use with the right and leftmembers, a linear antenna connected to a movable element of the firstgroup of said switching means, a coil antenna having coupling means forcoupling said coil antenna to a radio receiver, said coil antennaconnected to one of the fixed members of said first group of switchingmeans} said radio receiver connected to two movable members of saidsecond group of switching means, a head set comprising telephonereceivers for use with a right and lefthand ear, said telephonereceivers having separate electrical connections connected to the fixedmembers of said second group of switching means, and means forsimultaneously operating the'movable members of said second group ofswitching means with the movable members of said first group ofswitching means so that the telephone receiver for the lefthand ear andthe receiver for the righthand car are changed over in synchronism withthe changes in connection of said antenna.

- AUGUST 'LEIB.

